This invention relates to an improved wall for resisting lateral forces imposed on a building incorporating the improved wall. Specifically, this invention relates to a wall in a light-frame building having within it a sub-component specifically designed to resist lateral forces imposed on the building such as those caused by an earthquake or by wind loading. The present invention improves on precedent wall designs in light-frame construction by providing a structure that the designer can confidently predict will resist the lateral forces for which it is designed.
All structures must be designed to resist lateral forces. Current methods for improving the lateral resistance of light-frame construction walls have focused on adding components to a wall built according to conventional practices. In light-frame construction, the simplest such wall consists of a bottom plate, studs resting on and connected to the bottom plate, and a top plate resting on and connected to the studs. Openings for windows and doorways may be incorporated into the light-frame wall.
One of the earliest methods for bracing a wall against lateral forces was to incorporate bracing into the frame of the wall in the form of diagonal bracing members. Another simple means of providing lateral resistance was to provide sheathing to the frame. Plywood sheathing and Oriented Strand Board are common sheathing materials used today in conventional light-frame construction.
As light-frame construction design became more sophisticated, foundation anchors were added to connect the bottom plate of the wall to the foundation to prevent the wall from slipping off the foundation. Later on it was realized that certain walls were light enough to lift up under moment reactions caused by lateral forces and so needed to be further anchored with brackets called holdowns, which attach to the studs of the wall and to bolts set into the foundation.
With proper design and installation, these conventional methods of providing lateral resistance by applying sheathing, foundation anchors and anchored holdowns to conventional walls can provide acceptable resistance to most lateral forces. However, proper installation can be a problem using conventional methods. The division of labor on job cites can result in improper connections. Furthermore the installer may cut corners and sacrifice resistance to lateral forces in return for ease of installation or aesthetic considerations.
The present invention improves on conventional methods for providing lateral resistance by minimizing the possibility of variation in the installation of the component that will be responsible for providing lateral resistance.